Darke by Angie Sage

What a great way to end the Septimus Heap series.  An evil Darke has enveloped the castle and starts to take over the village as well.  Marcia accidentally banishes Alther and Septimus must return him in order to hopefully end Merrin's terror over the castle.  Merrin is still determined that he was suppose to be Septimus and is intent on taking revenge on him.  Jenna finally accepts that she is to be a princess and must act accordingly and think of everyone else as well as her safety, however, the Coven witches are determined to make her a witch.  Sounds crazy and a lot is going on, but Angie does a great job tying up all the lose ends and ending this fun story.